Section 5: Metamorphic Rocks Chapter 5: Rocks Section 5: Metamorphic Rocks

Metamorphic Rock from Greek: meta = “change”, morphosis = “form” heat and pressure deep beneath Earth’s surface can change any rock into metamorphic rock

How Rocks Change Can change appearance, texture, crystal structure, and mineral content Collisions between plates can push rock down toward mantle or pockets of magma can rise High temperatures change size and shape of grain and extreme pressure squeezes rock so tightly that the mineral grains may line up in flat, parallel layers

Checkpoint 1 What are two ways that rocks can be exposed to intense heat sufficient to turn them into metamorphic rocks?

Checkpoint 1 What are two ways that rocks can be exposed to intense heat sufficient to turn them into metamorphic rocks? They can be pushed down toward the mantle through plate tectonics or pockets of magma can rise.

Types of Metamorphic Rocks Classified according to arrangement of grains that make up the rocks Types: Foliated Nonfoliated

Checkpoint 2 How are metamorphic rocks classified?

Checkpoint 2 How are metamorphic rocks classified? According to arrangement of grains

Foliated Rocks Have their grains arranged in parallel layers or bands Folio is Latin for “leaf” May split apart along bands E.g. slate (from shale), gneiss (from granite)

Nonfoliated Rocks Mineral grains are arranged randomly Don’t split into layers E.g. quartzite (from sandstone)

Nonfoliated vs. Foliated Rocks

Checkpoint 3 What is the difference between foliated and nonfoliated rocks?

Checkpoint 3 What is the difference between foliated and nonfoliated rocks? Foliated rocks are arranged in layers.

Uses of Metamorphic Rock Certain metamorphic rocks are important materials for building and sculpture Marble (from limestone) Fine, even grain – can be cut into thin slabs or carved into many shapes Easy to polish – buildings and statues Slate Variety of colors Splits easily into flat pieces – flooring, roofing, outdoor walkways, chalkboards

Checkpoint 4 Why are metamorphic rocks useful?

Checkpoint 4 Why are metamorphic rocks useful? Marble: fine, even grain; can be cut into thin slabs or carved; easy to polish Slate: splits evenly into flat pieces

Post-lesson Quiz How are metamorphic rocks classified? a. by the arrangement of their grain b. by the color of their grain c. by the size of their grain d. by the texture of their grain

Post-lesson Quiz What can change about a rock when it becomes metamorphic? a. texture b. crystal structure c. mineral content d. all of the above

Post-lesson Quiz 3. What two things do metamorphic rocks need to form? a. electricity and air b. heat and pressure c. heat and water d. pressure and water

Post-lesson Quiz What is the heat source for transforming metamorphic rocks? a. lava b. the Sun c. magma d. thermal vents

Post-lesson Quiz 5. Which of the following is not a metamorphic rock? a. slate b. limestone c. marble d. gneiss